Abstract Stroke is one of leading causes of death and disability worldwide, mainly affecting elderly. Tissue plasminogen activator (tPA), the only Food and Drug Administration (FDA) approved treatment, is limited in its use to < 8.5% of stroke patients. Therefore, there is a compelling need to develop new and broader utility therapies for acute ischemic stroke. Vepoloxamer is a well characterized proprietary amphipathic copolymer with rheological properties, which is currently under investigation in a global phase III clinical trial for patients with sickle cell disease. Our preliminary studies demonstrate that administration of Vepoloxamer in combination with tPA 4h after embolic stroke facilitates recanalization and thrombolysis reduces ischemic neuronal damage and improves neurological outcome, but does not increase cerebral hemorrhage in young adult rats. We also found that platelet-derived exosomes contribute to the therapeutic effect of Vepoloxamer on enhanced tPA-thrombolysis. In this application, we propose to investigate effect of Vepoloxamer in combination with tPA on acute stroke and molecular mechanisms underlying the combination therapy on the thrombolysis and neurovascular function in the aged male and female rats. Data generated from this application may provide a novel and potentially useful treatment strategy for patients with acute stroke.